Cyanide product and process of producing the same



- Ratented Sept. 7,1926.

UNITED STATES A E OFFICE-7.

xsNNn'riI F. Coornn, or (mm-r NECK, NEW YORK, AssIo on ro AMERICAN OYANA- Y MID COMPANY, or NEW YORK, Y., A CORPORATION or MAINE.

OYANIDE PRODUCT AND PROCESS OF PBODU GII IG THE SAME.

Ho Drawing.

This-invention relates to a c anide product and process of producing t e same, and has for its object to provide a product and a procedure which is more desirable in prac- 5 tice than those heretofore proposed.

' With-these andother objects in view the invention consists in the novel article of manufacture' constituting the product and in the novel steps and combinations of steps 1' fully hereinafter disclosed and particularly pointed out in the" claims.

In order that the invention maybe the more clearly understood it is said :-'It is well known thatin the production of commercial Cyanides by such processes as yield their final products from aqueous solutions through evaporative or drying procedures to effect their ultimate recoveries, ithas been found impossible to produce a'commercially pure white product within the limits of costs. That is, even though the original solution contains, for example, practically only sodium cyanide, by the time it is evaporated and dried, it will be found that adecomposition has set in, and the best product produced by this procedure -will only run from say 90% to 94% sodium cyanide, with i an average content of about 92% sodium'cyanide. The bulk of the remaining constitu- 'ents will generally be found to consist of sodium carbonate and sodium hydroxide With the former predominating, together with various unknown organic decomposition products. Should'cyanides derived in this manner from aqueoussolutions be fused it is further well known that experience.

shows that a further decomposition sets in, and the, resulting product, instead of being Color due to'such further decomposition. It is-- therefore the common pract ce to avoid fusing these products in ordinary cases and to briquette the same, which of course is point as would be a fusing procedure.

In carrying out this on ,the other hand, the foregoing ob ections are-obviatedas-follows: To a sodium cya- Application illed Kay 29, 1923. Serial No. 642,839.

constituting the process all as will be more produced during the reaction floats on top ,whit'e takes on a more or less gray to a black not'so desirable from a commercial stand-" than the original crystallized cyanide that was placed in the fusion pot.

. As an example of this procedure, one may take a low rade cyanide crystal or dryer product ana yzing say 58% sodium cyanide and add it to say 5% of its weight of essentially anhydrous sodium ferrocyanide Na; Fe(CN) and after mixing these compounds charge the mixture into a fusion a B5 pot and melt the mass. The iron that is of the molten bath and is agglomerated in to a spongy mass, when it is skimmed off. The molten iron free product is now con-- yemently cast into molds when upon cool-' mg it will be found to consist of a pure white marble like product analyzing say- 60% sodium cyanide.v 'The amount of anhydroussodium ferrocyanide which is used n each nstance will be proportioned to the 1mpur1t1es,present in the original cyanide to be raisedin grade. I may safely add up to say two and a half timesthe-weight of these impurities in the form of essentially anhydrous sodium ferrocyanide in carrying out this invention. On the other hand, it is 1' not necesary ,to use .so much, anhydrous sodium ferrocyanide if one merelydesires 'to still further improve a fairly high grade of cyanide of so 'um. Especially is this true when using a grade containing say 4 80% or of crude cyanide. .Insuch case an addition of anhidrous sodium ferrocyanide-of say 5% oft e weight of the original cyanide is suflicient to clarify the mass and produce a high grade product.

From the-foregoing it will be seen that this invention not only provides a procedure for raising the grade of a crude c anide after the same has n recover from anaqueous solution, but it also provides a fused product consisting of a pure white marble like mass of cyanide of ahigher grade than I was the original mass.

What is claimed is: 1. The process of impro' g the quahty of a crude cyanide. containing decomposi- -tion products which consists adding a ferrocyanide tosaid crude cyanide; fusing the mixture .thns produced; removing any iron that may separate out durmgthe fu-' 'sion'; and cooling and recovering'the iron 'freeproduct thus produced.

2. .The process of improving the grade of a crude-cyanide of the alkali class deduring the fusion process; andcooling and.

recovering the resulting iron free fused product. a

3. The process of improving the grade of an impure alkali metal cyanide derived from an aqueous solution and containingalkali metal hydroxide or carbonate or both which consists in adding to' said cyanide an alkali metal ferrocyan'ide; fusing the mix-' ture thus-produced; removing any iron set free by the fusion of said mixture; and recovering the resulting improved fused iron 5 in adding to said, cyanide a quantity of sodium ferrocyanide; fusing the mixture thus produced; separating "out any iron set free during the process of fusion; and casting in molds the resulting iron free and improved sodium cyanide.

In testimony. whereof I aflix my signature.

KENNETH F. COOPER. 

